air separation unit for oxy-coal combustion systems
TRANSCRIPT
Air Separation Unitfor Oxy-Coal Combustion
S tSystems
Jean-Pierre TranierJean-Pierre TranierRichard Dubettier
Nicolas PerrinAir Liquideq
1st International Oxyfuel Combustion Conference, CottbusSeptember 9, 2009
Current state of the art for ASU
ASU optimized for oxycombustion
Integration of ASU in overall oxycombustion solution
Net Plant Efficiency Comparison
Gross/Net power consumption of ASU
21st International Oxyfuel Combustion Conference, Cottbus 09/09/09
ASU optimized for oxycombustionCryogenic production of oxygen has been used for more
From today’s most efficient ASUs
Cryogenic production of oxygen has been used for more than 100 years but is still improving
& the world’s largest ASUs
ISAB IGCC (2x 1800 tpd O2) Operation since 1999
Sasol Train 15 (4200 tpd O2 MSL)Operation since 2003 (copy order in 2007)Ope at o s ce 999
… to a new specific design for oxycombustion
p ( py )
...with additional power reduction through cycle integration
31st International Oxyfuel Combustion Conference, Cottbus 09/09/09 .3
130
ASU optimized for oxycombustion
110
120
pend
iture
90
100
d ca
pita
l exp
70
80
Nor
mal
ized
60120 140 160 180 200 220 240 260 280
Specific energy of separation (kWh/t)
20% improvement has already been achieved todayin specific energy consumption
41st International Oxyfuel Combustion Conference, Cottbus 09/09/09
CPU
Integration : process simulation
FG Cleaning & Recycle
CPU
St
Performance
Boiler
Steam Turbine Cycle
Pulverizer
51st International Oxyfuel Combustion Conference, Cottbus 09/09/09
ASU
.5
Net Plant Efficiency ComparisonCO2 capture from pulverized coal plants is possible with
50.0without CCS with CCS
Babcock & Wilcox / Air Liquide 2008
results
2penalty of only ~6 percentage pts
28 3
39.4
29 3
33.632.1
39.4
35.0
40.0
45.0
% (H
HV
)
28.3 29.3
20.0
25.0
30.0
Effi
cien
cy
5.0
10.0
15.0
Net
Pla
nt
0.0SC PC
Air-FiredSC PCAir-Fired
IGCC Avg SC PCOxy-Fired
B&W / ALSC PC
Oxy-Fired
IGCC Avg
Amines
TECHNOLOGY
61st International Oxyfuel Combustion Conference, Cottbus 09/09/09 .6
SP PC = Super Critical Pulverized Coal – IGCC = Integrated Gasification Combined Cycle
Data from DOE/NETL reports and B&W – Air Liquide studies (2007 – 2008)
Cycle analysisFor a 550 MWe net, an HHV efficiency of 33.6%For a 550 MWe net, an HHV efficiency of 33.6% can be achieved today with the following results :
MW Esep ASUp(kWh/t)
Gross power from steam 724.1
G f ASU 75 8 160Gross power for ASU 75.8 160
Gross power for CO2 CPU 62.4
Primary FD & ID fans & 35 9Primary, FD & ID fans & miscellaneous
35.9
Sub-total Auxiliary load 174.1
Net plant power 550.0
71st International Oxyfuel Combustion Conference, Cottbus 09/09/09
Gross/Net power consumption of ASUHeat integration :Heat integration :
Adiabatic compressionOxygen preheating to approx. 150 °CCondensates preheating to approximately 150 °CCondensates preheating to approximately 150 CGain : 5.6 MW
Net power of ASU: 70.2 MW (i.e. Esep = 145 kWh/t)
Another benefit of oxycombustion is to decrease the flue gas flow and therefore the heat losses gassociated with the flue gas condenser ; this gain has been evaluated at 8.1 MW for a 550 MWe net plantp
Therefore the net penalty associated with the oxycombustion route (without CCS) is 62 1 MW
81st International Oxyfuel Combustion Conference, Cottbus 09/09/09
oxycombustion route (without CCS) is 62.1 MW
Further ASU improvements
Specific energy reduction
Capital expenditure reduction
Advanced cryogenic ASU concept
91st International Oxyfuel Combustion Conference, Cottbus 09/09/09
Specific energy reduction
Higher efficiency of new large air compressorsHigher efficiency of new large air compressorsAdditional power savings with new process cyclesF th d ti ith th d l t fFurther reduction with the development of new technologies
A further gain of 10 % is targeted for 2015
200 kWh/t Specific energies
160 kWh/t145 kWh/t
energies without heat integration
101st International Oxyfuel Combustion Conference, Cottbus 09/09/09
MW MW Delta
Specific energy reduction
2008 study
2015 target
Gross power from steam 724.1 729.8 +0.8%
Gross power for ASU 75.8 68.2 -10%
Gross power for CO2 CPU 62.4 56.2 -10%
Primary, FD & ID fans & miscellaneous
35.9 37.3 +3.9%
Sub-total Auxiliary load 174.1 161.7 -8%
Net plant power 550.0 568.1 +3.3%
HHV efficiency 33.6% 34.7% +1.1pt
Net power of ASU with heat integration is targeted at 130 kWh/tCO2 capture from pulverized coal plants is expected to
111st International Oxyfuel Combustion Conference, Cottbus 09/09/09
achieve only 4.7 percentage pts penaltyWith USC cycle (700°C), the HHV efficiency could be above 40%
Capital expenditure reduction
A capital expenditure reduction program hasA capital expenditure reduction program has been launched on the ASU for oxycombustion with a target of -20%
121st International Oxyfuel Combustion Conference, Cottbus 09/09/09
Advanced ASU conceptHigh pressure cycle with nitrogen production atHigh pressure cycle with nitrogen production at high pressure instead of atmospheric pressure
350°CAir
11 bar absAdiabatic compression
Hot nitrogenASU
330°C5 bar abs
Hot oxygen
131st International Oxyfuel Combustion Conference, Cottbus 09/09/09
ASU integration to produce additional power with
Advanced ASU conceptASU integration to produce additional power with a dual Rankine (steam) / Brayton (N2) cycle
Boiler Steam turbine
Nitrogent 330°C
Nitrogen out 620°C or higher
at 330°C
350 °C
Nitrogen turbine
BFW350+°C
ASU
141st International Oxyfuel Combustion Conference, Cottbus 09/09/09
ASUOxygenat 330°C Air compressor
Advanced ASU conceptLower specific energy of separation : approx. -15 % i.e. p gy p pp110 kWh/tLower CAPEX for the Air Separation Unit : higher pressure means smaller equipment and increased trainpressure means smaller equipment and increased train size (up to 7500 t/d)Compressor and turbine offer has to be developedHi h l l d d t t d f IGCCHigh pressure cycle already demonstrated for IGCC applicationPuertollano (Spain) Yokohama (Japan)( p ) ( p )
Most efficient ASU in the world
151st International Oxyfuel Combustion Conference, Cottbus 09/09/09
Conclusions
Oxycombustion is today the most efficient route for CCSCCS
Further improvements in the Air Separation Unit are targeted both in term of Power consumption andtargeted both in term of Power consumption and Capital expenditure reduction
Advanced cryogenic Air Separation Unit concept is a potential breakthrough for the oxycombustion route
161st International Oxyfuel Combustion Conference, Cottbus 09/09/09
Acknowledgement
B b k & Wil fBabcock & Wilcox for heat integration studies
Contactsjean-pierre tranier@airliquide comjean [email protected]
[email protected]@airliquide.com
Specific energy of separation : definitionPower required to produce 1 metric ton of pure oxygen contained in a q p p yggaseous oxygen stream at a given oxygen purity at atmospheric pressure (101325 Pa) under ISO conditions (15°C, RH 60%)
Driver efficiency (EM ST GT) not taken into account : power at shaftDriver efficiency (EM, ST, GT) not taken into account : power at shaft
Heat of regeneration of driers (steam, natural gas or electrical) not included
Power consumption of cooling system (CW pumps, fans,…) not included
Specific energy of production = Specific energy of separation + specific energy of compression
Specific energy of compression ≈ 0.1xQ(Nm3/h)xlog10(PGOX/PATM)1 t/h of GOX ≈ 1000 / 1.427637 ≈ 700 Nm3/hFor 1.4 bar abs : 10 kWh/t of pure O2
181st International Oxyfuel Combustion Conference, Cottbus 09/09/09